Am polishing the interior of hollow waee



(No Model.) 2 Sheets-Sheet 1.

J T. DUFF. MACHINE FOR GRINDING AND POLISHING THE INTERIOR OF HOLLOWWARE.

Patented Sept. 6, 1887.

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(No Model.)

J T.. DUFF.

MAGHINE FOR GRINDING AND POLISHING THE INTERIOR 0P HOLLOW WARE.

at ted Sept. 6; 1887.

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' llNi-rnn ra rns Ar IN'I rrica JOHN T. DUFF, OF PITTSBURG,PENNSYLVANIA, ASSIGNOB TO A. M. DUFF, A. NEGLEY, AND H. G. HUGUS, ALL OFSAME PLACE.

MACHINEIOR GRINDING AND POLISHING THE lNTERlOR F HOLLOW WARE.

SPECIFICATION forming part of Letters Patent No. 369,326, datedSeptember 6, 1887.

Application filed November-11, 1856. Serial No. $8.643.

To all whom it may concern:

Be it known that I, J OI-IN T. DUFF, a citizen of the United States,residing at Pittsburg, in the county of Allegheny and State ofPeuusylvania, have invented certain new and useful Improvements inMachines for Grinding and Polishing the Interior Surface of Hollow are;and I do hereby declare the following to be a full, clear, and exactdescription of the m invention, such as will enable others skilled inthe art to which it pertains to make and use the same, reference beinghad to the accompanying drawings, which form a part of thisspecification. 1 illy'invention relates to a machine for grinding andpolishing the interior surface of hollow ware, the object being toprovide a means whereby all sizes and shapes of hollow waresuch aspots,frying-pans, &c.may be ground and polished on the inside surface ina simple manner and at small initial cost; and with such end in view myinvention consists in a means for holding the article to be ground inposition, an adjustable device for grinding or 2 5 polishing the innersurface of the same, together with certain other details of constructionand combination of parts, as will be fully described hereinafter, andpointed out in the claims.

In the accompanying drawings, Figure 1 is a side elevation of myimproved inside grinding or polishing machine constructed in accordancewith my invention, which I have partly shown in section the better toshow its inner 5 working parts. Fig. 2 is a plan view of the same, aportion of which is in section, showing the position of thegrinding-wheel while operating on the bottom of a deep vessel. Fig. 3 isan end elevation of the holder, designed to show the position of theseveral catches or bolts constituting the-locking device. Fig. 4 is anenlarged front sectional elevation of one of the bolts for securing thepiece in the holder. Fig. 5 is a side sectional elevation of the same.

To construct a grinding and polishing machine in accordance with myinvention I provide a standard or strong post, 1, and attach the same bybolts 2 to the center of an oblong base-plate, 3. Across the top of thisstandard 50 1, I form a dovetail slide, 4, in which a small (No model.)

carriage or table, 5, is secured, capable of moving across the standard1 transversely to the length of the machine, and actuated by ahandwheel, 6, and threaded shaft 7, attached to the carriage 5 andpassing through a threaded lug 5 5 on the standard 1. Across thiscarriage 5, in the direction of the length of the apparatus, I secure insuitable bearings, 8, astout shaft, 9, having attached thereto a smalldrivingpulley, 10. To each end of shaft 9, I secure, by means of ascrew-thread, a hollow conical holder, 11, whiclrin practice are madeinterchangeable to conform to the various sizes of the hollow ware to beground. About the front perimeters of these holders 11,1 arrange 6 5 twoor more springbolts, 12, consisting of a bolt, 12, actuated byaspiralspring, 13, placed in a cavity, 14, formed at suitable intervals aboutthe perimeter of the holders 11. A recess is formed in the edge of theholder at :0, into which the handle of the article is fitted, therebyserving to hold the article in place. To one side of this centralstandard, 1, I erect another, 15. A sliding carriage, 16, is moved insuitable guideways on the standard to- 7 5 ward and from the holder 11by means of a tooth-rack, 17, formed on the under side of the carriage,a small pinion, 18, mounted on a shaft, 19, and a hand-wheel, 20. Acrossthe top of this carriage 16, and at right angles to the movement of thesame, I form another slide, 21, in which I place a sliding table, 22,the position of which is regulated and controlled by a hand-wheel, 23,attached to a threaded shaft, 24, that is secured to the table 22, andworks in a threaded lug on the carriage 16. On the top of this table 22,I pivot an annular plate, 25, and secure the same by set-screws 29,placed through circumferential slots 30, which allows the plate 25 alimo ited curvilinear movement. Across the top of this annular plate 25,I secure in suitable bearings, 36, along shaft, 31, having secured toone end thereof a small emery or grinding wheel, 32. Between thebearings 36 of this shaft 31, I secure a tight and loose pulley, 32,which, in connection with an overhead pulley of a width equal to thelength of the entire movement of the carriage 16, gives the shaft 31 arapid rotary movement on its axis. This 103 grinding-wheel 32, I formwith a portion of its perimeter beveled, which part grinds or polishesthe bottom of the vessels 33 and 34.

At the other side of the central standard, 1, I construct an apparatusanalogous in every part to that described, thus forming a doublegrinding and polishing machine.

With this-machine deep or shallow vessels 33 34 may be ground orpolished on their entire inner surface by the same wheel 32. At theright-hand side of the central post, 1, (see Fig.

2,) I have shown the holder 11 and deep vessel 34 in section, in whichthe grinding-wheel 32 is about to cross the bottom, while at Fig. 1, tothe left of the central standard, I have shown a shallowvessel, 33,secured in position.

In operation a rapid rotary motion is given to the holders 11 and thegrinding-wheel 32, the one rotating in an opposite direction to theother. The article to be ground or polished is forced into the holders11, and secured in that position by the spring-bolts 12, together withthe handles 37 of the vessels placed in recesses formed in the sides ofthe holders 11, which prevents the article from revolving inside thesame. By means of the threaded shafts 24 and 7 and hand-wheels 23 and 6the holders 11 and grinders 32 are adjusted to correspond to the size ofthe vessel to be polished. The grinding-wheel 32, occupying the positionshown at the left of the central standard, 1, the operator places onehand on the wheel 20 and the other on the handle 35, projecting from theannular plate 25. By revolving the hand-wheel 20 the carriage 16 movesslowly toward the holder 11, carrying the grinding-Wheel 32 down theinner side of the vessel 33 34, which, being in rapid motion in areverse direction to that of the grindingwheel 32, scours or grinds thesurface until the bottom of the vessel is reached, at which time thewheel 32 is inclined or at an angle with the bottom. By the use of thehand-wheel 23 and threaded shaft 24 the grinding-wheel 32 is movedtoward the center of the vessel 33 34, thus completing the article,which is now taken out of the holder 11, and another put in place andthe same operation repeated.

Having thus described my invention, what I claim,and desire to secure byLetters Patent, 1s-

1. In a machine for grinding and polishing the interior of hollow ware,the combination of the supporting-frame, the rotatable holder, itscarriage, the track or guideway transverse to the axis of the holderinwhich the carriage moves, the grinder, and the grinder-carriageadjustable toward and from the holder transversely thereto and at anangle therewith, substantially as set forth.

2. The herein-described holder for hollow Ware, having an automaticspring catch or detent at its outer edge adapted to rest against theedge of the vessel when in position.

3. The herein-described holder for hollow ware, having a spring catch ordetent at its outer edge and a recess for the handle of the vessel.

JOHN T. DUFF.

"Witnesses:

M. E. HARRISON, D. O. NEGLEY.

